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Médias (1)
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Revolution of Open-source and film making towards open film making
6 octobre 2011, par
Mis à jour : Juillet 2013
Langue : English
Type : Texte
Autres articles (54)
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Modifier la date de publication
21 juin 2013, parComment changer la date de publication d’un média ?
Il faut au préalable rajouter un champ "Date de publication" dans le masque de formulaire adéquat :
Administrer > Configuration des masques de formulaires > Sélectionner "Un média"
Dans la rubrique "Champs à ajouter, cocher "Date de publication "
Cliquer en bas de la page sur Enregistrer -
Contribute to documentation
13 avril 2011Documentation is vital to the development of improved technical capabilities.
MediaSPIP welcomes documentation by users as well as developers - including : critique of existing features and functions articles contributed by developers, administrators, content producers and editors screenshots to illustrate the above translations of existing documentation into other languages
To contribute, register to the project users’ mailing (...) -
Formulaire personnalisable
21 juin 2013, parCette page présente les champs disponibles dans le formulaire de publication d’un média et il indique les différents champs qu’on peut ajouter. Formulaire de création d’un Media
Dans le cas d’un document de type média, les champs proposés par défaut sont : Texte Activer/Désactiver le forum ( on peut désactiver l’invite au commentaire pour chaque article ) Licence Ajout/suppression d’auteurs Tags
On peut modifier ce formulaire dans la partie :
Administration > Configuration des masques de formulaire. (...)
Sur d’autres sites (7118)
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Java Playing Sound From YouTube
8 mai 2022, par etkmlmI'm in a LWJGL game and want to play sound from YouTube. I have the stream link but can't play it anymore.


public void playMusic(Music m) throws IOException {
 String uri = m.getUrl();
 URL url = new URL(uri);
 try{
 Process p = new ProcessBuilder().command("ffmpeg.exe", "-i", uri, "-acodec", "pcm_u8", "-ar", "22050", "-f", "wav", "pipe:1").redirectError(ProcessBuilder.Redirect.INHERIT).start();

 AudioInputStream str = AudioSystem.getAudioInputStream(p.getInputStream());
 Clip clip = AudioSystem.getClip();
 clip.open(str);
 clip.start();

 }
 catch (Exception e){
 e.printStackTrace();
 }

}



It throws "Chunk size too big" error. I started ffmpeg alone but in this time, ffmpeg throws "invalid argumentsize=" error.


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FFmpeg cant recognize 3 channels with each 32 bit
4 avril 2022, par ChryfiI am writing the linearized depth buffer of a game to openEXR using FFmpeg. Unfortunately, FFmpeg does not adhere to the openEXR file specification fully (like allowing unsigned integer for one channel) so I am writing one float channel to openEXR, which is put into the green channel with this command
-f rawvideo -pix_fmt grayf32be -s %WIDTH%x%HEIGHT% -r %FPS% -i - -vf %DEFVF% -preset ultrafast -tune zerolatency -qp 6 -compression zip1 -pix_fmt gbrpf32le %NAME%_depth_%d.exr
.

The float range is from 0F to 1F and it is linear. I can confirm that the calculation and linearization is correct by testing 16 bit integer (per pixel component) PNG in Blender compositor. The 16 bit integer data is written like this
short s = (short) (linearzieDepth(depth) * (Math.pow(2,16) - 1))
whereas for float the linearized value is directly written to OpenEXR without multiplying with a value.

However, when viewing the openEXR file it doesn't have the same "gradient" as the 16 bit png... when viewing them side by side, it appears as if the values near 0 are not linear, and they are not as dark as they should be like in the 16 bit png.
(And yes, I set the image node to linear), and comparing it with 3d tracking data from the game I cant reproduce the depth and cant mask things using the depth buffer where as with the png I can.


How is it possible for a linear float range to turn out so different to a linear integer range in an image ?


UPDATE :


I now write 3 channels to the ffmpeg with this code


float f2 = this.linearizeDepth(depth);

buffer.putFloat(f2);
buffer.putFloat(0);
buffer.putFloat(0);



the byte buffer is of the size
width * height * 3 * 4
-> 3 channels with each 4 bytes. The command is now-f rawvideo -pix_fmt gbrpf32be -s %WIDTH%x%HEIGHT% -r %FPS% -i - -vf %DEFVF% -preset ultrafast -tune zerolatency -qp 6 -compression zip1 -pix_fmt gbrpf32le %NAME%_depth_%d.exr
which should mean that the input (byte buffer) is expecting 32 bit floats with 3 channels.

FFmpeg is somehow splitting up channels or whatever... could be a bug, could be my fault ?


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Writing linear float range to openEXR turns out non linear
3 avril 2022, par ChryfiI am writing the linearized depth buffer of a game to openEXR using FFmpeg. Unfortunately, FFmpeg does not adhere to the openEXR file specification fully (like allowing unsigned integer for one channel) so I am writing one float channel to openEXR, which is put into the green channel with this command
-f rawvideo -pix_fmt grayf32be -s %WIDTH%x%HEIGHT% -r %FPS% -i - -vf %DEFVF% -preset ultrafast -tune zerolatency -qp 6 -compression zip1 -pix_fmt gbrpf32le %NAME%_depth_%d.exr
.

The float range is from 0F to 1F and it is linear. I can confirm that the calculation and linearization is correct by testing 16 bit integer (per pixel component) PNG in Blender compositor. The 16 bit integer data is written like this
short s = (short) (linearzieDepth(depth) * (Math.pow(2,16) - 1))
whereas for float the linearized value is directly written to OpenEXR without multiplying with a value.

However, when viewing the openEXR file it doesn't have the same "gradient" as the 16 bit png... when viewing them side by side, it appears as if the values near 0 are not linear, and they are not as dark as they should be like in the 16 bit png.
(And yes, I set the image node to linear), and comparing it with 3d tracking data from the game I cant reproduce the depth and cant mask things using the depth buffer where as with the png I can.


How is it possible for a linear float range to turn out so different to a linear integer range in an image ?